Technical Transactions iss. 17. Chemistry iss. 1-Ch

Technical Transactions iss. 17. Chemistry iss. 1-Ch

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Collection items (11)


The Computational-Fluid-Dynamics study of an unbaffled stirred vessel with eccentrically positioned impeller

Wójtowicz, Ryszard, Lipin, Andrey A.
Article
2015
The paper presents the results of CFD simulations of liquid flow in an unbaffled stirred vessel with an eccentrically positioned impeller. The influence of the impeller’s distance from the tank axis (eccentricity) on the generated flow circulation was analyzed. Based on numerical modelling, the flow pattern, vortex formation as well as turbulence parameters in selected stirred vessel zones were determined. Obtained results were presented as vector/contour maps, and iso-surfaces of Q- criterion for identification of vortex cores. Additionally, for each investigated stirred vessel power consumption was calculated.

Scaffolds for tissue engineering

Pluta, Klaudia, Malina, Dagmara, Sobczak-Kupiec, Agnieszka
Article
2015
The paper presents the current trends in medicine of regenerative tissue defect caused by resection of tumors or fractures. Although it is a relatively young field of science, it creates new possibilities for the reconstruction of pathologically altered tissue with the use of three-dimensional scaffolds. Tissue engineering places particular emphasis on the type of scaffold from which they are made because of a number of requirements of medical materials including biocompatibility, mechanical strength and porosity.

Modification of expandable polystyrene beads

Malewska, Elżbieta, Prociak, Aleksander
Article
2015
This paper presents the effect of modification of expandable polystyrene beads (PSB) with an additional amount of physical blowing agent and the addition of ethylene wax on their properties. Three different sizes of PSB beads were analyzed. The bulk density and thermal properties – thermogravimetric and differential scanning calorimetry were evaluated.

Power industry – coal ecology

Machowska, Halina
Article
2015
In this work, the fuel structure of electric energy production is presented, and also the coal-based power industry influence on the environment, greenhouse effect, mercury emissions from coal burned by power stations. EU requirements regarding limits of mercury emissions, as well as methods and techniques enabling reduction of mercury emissions originating from coal burning processes.

Heat conduction in the ground under natural conditions and with heat exchanger installed

Larwa, Barbara, Kupiec, Krzysztof, Komorowicz, Tadeusz, Neupauer, Krzysztof
Article
2015
The results of calculations of the heat transfer in a horizontal ground heat exchanger are presented. The applied model is based on a one-dimensional equation of the transient heat conduction with an internal heat source. The model was correctly verified by comparison of computational results and experimental measurements presented in literature. Thermal calculations concerning heat transfer in the ground under natural conditions are also presented.

Flax fibers as natural filler for rigid polyurethane-polyisocyanurate foams based on bio-polyol from rapeseed oil

Kurańska, Maria, Prociak, Aleksander
Article
2015
The influence of flax fibers on the physical and mechanical properties and the flammability of rigid polyurethane-polyisocyanurate foams obtained from rapeseed oil-based polyol was analyzed. The rigid polyurethane-polyisocyanurate foams with apparent density of 40−48 kg/m3 were prepared. It has been found that the introduction of flax fiber has a beneficial effect on selected properties of obtained foams.

Performance analysis of reinforced polymer cement mortars “RPCMs” used for repairing concrete structures

Kozak, Aleksander, Bonopera, Marco
Article
2015
Concrete structures operating under different environmental conditions are subject to the action of aggressive gaseous and liquid media, which leads to their degradation. Even well-designed buildings, after time, can have problems to fulfil appropriate requirements concerning their further service life. Fiber reinforced mortars based on cement modified with different types of polymers are commonly used materials for renovating concrete structures. They should fulfil requirements concerning their high adhesion to concrete, minimum tensile strength, compatibility with repaired concrete and low shrinkage. The aim of the work was to compare the performance of three reinforced PCMs based on various polymers. The following features were tested: adherence to concrete, shrinkage and flexural strength.

Efficient methods for synthesis of florol and its derivatives

Jaśkowska, Jolanta, Chorabik, Karolina, Majka, Zbigniew
Article
2015
The paper describes and compares the two methods of synthesis of florol (1) (4-methyl-2-(2-methylpropyl) tetrahydro-2H-pyran-4-ol) by the Prins reaction. The first method involves the reaction for obtaining 1 in methylene chloride as solvent at 60°C. The second method applies the preparation of florol (1) and other tetrahydrofuran derivatives in solvent-free conditions in room temperature.

On adsorption of water vapor on silica gel

Gwadera, Monika, Kupiec, Krzysztof, Marszałek, Andrzej
Article
2015
The aim of this work is to present the results of studies on heat and mass transfer in an adsorber, which is the main part of an adsorption chiller. The paper refers to adsorption of water vapor on silica gel grains. Adsorbent grains were coated on the outer surface of a copper pipe. The influence of grains diameter and flow rate of the gas phase on process intensity was considered.

Modeling of adsorption in a mixing tank

Gwadera, Monika, Kupiec, Krzysztof
Article
2015
Computational models for adsorption in a tank are presented. The approximate model provides the same results as the exact model. The diffusion coefficient of a dye in an adsorbent pellet and the mass transfer coefficient in a fluid phase were determined on the basis of the measurements of dye adsorption on the activated carbon. It was determined how the fraction of the resistance to mass transfer in the fluid to the overall mass transfer resistance changes during adsorption. It was found that, for the examined system, the main resistance to mass transfer is located in the liquid phase.